1. Field of the Invention
This disclosure relates generally to testing on integrated circuits, and more specifically, to a system and method for continuous testing of repetitive functional blocks on an integrated circuit.
2. Description of the Related Art
The International Electrotechnical Commission (IEC) is a global organization that prepares and publishes international standards for all electrical, electronic and related technologies. These standards serve as a basis for national standardization and as references when drafting international tenders and contracts and the like. Stringent safety integration levels from newer standards, such as the international standard IEC 61508, are being applied to various applications including those that were not traditionally required to meet relatively strict safety integration levels. The stringent safety integration standards are, however, soon to be pervasive in many applications, thus raising the standards and level of entry for those applications subject to the standards.
The 65 nanometer (65 nm) process is currently an advanced lithographic node used in volume manufacturing of semiconductors, such as including complementary metal-oxide-semiconductor (CMOS) and the like. At the 65 nm lithographic node and beyond, design for manufacturability is important to assure adequate yield and reliability. Additionally, even traditionally reliable silicon structures may be less reliable when implemented using the more advanced lithographic nodes. For example, a D-type flip-flop (DFF), which is conventionally a relatively reliable silicon structure, becomes more sensitive to leakage current or soft errors at the higher technology nodes. Safe and reliable operation of deep submicron products is an increasing problem, particularly when these semiconductor products are used in applications and products that must meet more stringent industry standards, such as the international standard IEC 61508 and the like. Adequate yield and reliability also become more difficult to achieve technology advances.
It is desired to ensure safe and reliable operation and to ensure adequate yield and reliability of deep submicron integrated circuit (IC) semiconductor devices. Many such devices include repetitive functional blocks, such as multiple logical channel implementations, multiple processor cells, etc. It is desired to ensure proper operation of each repetitive functional block provided on the IC. It is desired to provide continuous testing of the functional blocks during normal operation of the IC.